1. Field of the Invention
The present invention relates to an image processing apparatus, an image recording apparatus, an image reproducing apparatus, a camera system, a computer program, and a storage medium. More specifically, the present invention relates to image processing that is provided to cancel the redundancy of compressed image data in case there is no motion of the image between the frames, for use in a standard system with the Motion-JPEG2000 method being adopted.
2. Description of the Related Art
Conventionally, the image compression/expansion algorithms include the MPEG1/MPEG2/MPEG4 for motion pictures and the Motion JPEG which handles the still pictures as continuous frames.
Recently, the Motion-JPEG2000 standard is under development as a new intra-frame coding method for motion pictures utilizing the still image coding standard JPEG2000.
One of the differences between the MPEG method and the JPEG method is that the latter performs only the intra-frame coding. Not only this, another difference is that the former method has the ability to take correlations of the images in the same frame as well as the images between different frames and to increase the compressibility of images more.
The JPEG method, which handles the respective frames independently, has the ability to edit each frame, as compared with the former, and the error of one frame at the time of transmission does not affect other frames.
Thus, the MPEG method and the JPEG have the features respectively, and one of them is selectively used for different applications properly.
The Motion-JPEG2000 method utilizes the discrete wavelet transform (DWT) as the compression coding method. Japanese Laid-Open Patent Application No. 2001-309381 discloses a technique which carries out the compression coding of image data using the discrete wavelet transform.
In the technique of Japanese Laid-Open Patent Application No. 2001-309381, the discrete wavelet transform of the pixel values is performed and the correlation of the images between different frames is taken, and the redundancy of image data in case there is no motion of the image between the frames is canceled. Hence, the compressibility of image data can be increased.
However, after carrying out the discrete wavelet transform of the pixel values of image data, the above-mentioned technique takes the correlation of the images between different frames using the wavelet transform coefficients before quantizing and coding, and it is made to cancel the redundancy of image data in case there is no motion of the image between the frames.
Therefore, it is difficult for a standard system, which is provided to treat the data format of the Motion-JPEG2000 method, to make use of a codestream obtained through the above technique after the data compression. Moreover, it is impossible to leave a codestream which is obtained through the compression coding by the Motion-JPEG2000 method but the redundancy of the image data in case there is no motion of the image between the frames is not yet canceled.
Therefore, the codestream generated by the above technique has too small flexibility, and it cannot be easily used by the standard system in which the Motion-JPEG2000 method is adopted. In order to use such codestream, it is necessary to prepare a special system of exclusive use.